November 5, 2011

DIY Daft Punk Helmet

 For Halloween 2011 I was just about to give up on making something new and just go with an existing costume when I saw a gadget blog post for Volpin Studios Daft Punk Helmet, both the helmets Volpin has built are impressive but the Thomas one looked amazing to me when it was finished.  While I am not the biggest Daft Punk fan, I knew instantly this would not only be impressive to complete, but also be a lot of fun with the required electronic engineering.  With a final costume idea in mind and about 6 weeks of time before halloween I set off on another crazy DIY project.  In the end, while the helmet was not as perfect as others, the electronics made up for it and everyone who saw it give me the thumbs up. (See the build video at the bottom for more pictures)

Fist off I did a lot of research into how other people have made helmets.  Besides Volpin, tekparasite also had interesting build ideas and a lot of documentation.  Between them, many youtube videos and forums, I had more then enough information to plan out what I wanted to do.  Basically it boils down to three options for the helmet itself. There are high end solutions involving casting and molds, which have amazing results, but take too much time and would cost a lot.  Then there is the option to buy an existing mold, saving a lot of time, but still costing a lot.  Finally there is the cheap way of using cardboard and/or other helmets as a base.  I decided that my goal was to go with the cheap option and make the best helmet I could for around 50-60$, the end cost was closer to 75$ but I now have a lot of extra parts for future projects from buying things in bulk, so it was acceptable.

To get started I needed to get a helmet shape, to do this I searched for existing paper craft models I could use.  Luckily it was not hard to find one.  After getting the required programs to view and print the models, I had a pdf containing several pages of shapes to cut out.  I knew right away that the base size would not be large enough, so after creating a scale helmet and trying it on, I estimated that 110% scaling would cover the size I needed while not being too huge.

Next, I printed and cut out the pieces that I had rearranged and scaled in PhotoShop.  Then painstaking glued and re-cut them out of cardboard.  This gave me a sturdy base that I could build on without having to rely on fiber glass like most paper craft builders do.  I grabbed my glue gun and assembled the pieces and ended up with a base helmet that fit nicely but had room of the parts and pieces that would come later.  Because I skipped the ear pieces I cut two large round circles of cardboard and placed them inside the helmet to fill the empty spots.  Then using two soda cans I crafted the ears by bending cardboard in a ring.  Later soda can ends and plexiglass would cove the ends.

After crafting the helmet skeleton I took Bondo and smoothed out the cracks and blockly-ness of the paper craft base.  After letting it dry, I sanded for several hours with a rasp and various levels of sandpaper. Once that was round and smooth I repeatedly used a thick layer of white acrylic paint to further fill in spots, and then re-sanded.  Finally two coats of glossy black paint gave me the base helmet I needed to move on to the fun electrical parts.  (Time: two weeks of nights and weekends)

In between waiting for things to dry I created a set of gloves from black work groves and milk carton plastic.  This was covered by metal duct work tape and hot glued to the gloves.  I based the shapes off of Volpin's glove template and then adjusted it to fit a scanned trace of my hands.

Next came the part I was looking forward to.  I had already ordered 500 3mm red leds, 10 MAX7219CNG chips and other assorted leds and parts off of ebay before starting work on the helmet as I knew it would take 2-3 weeks to get them from China.  By the time I had the helmet ready everything had arrived.  I used my heat gun to bend a strip of plexiglass into shape and then carefully drilled 256 pairs (that is 512 individual holes!) using a 1/32 inch bit.  A rotery tool or drill press would have been nice, but a hand held drill got the job done without any accidents.  I used a paper template to mark each hole before drilling.  Then I trimmed and soldered each red led into vertical column, then after completing each column I would bend the annode and connect it to the previous led in the row.  This created groups of 64 leds, the cathode wires holding in the leds vertically and the annode wires holding the group together in rows.  After finishing each group of 64 I used some spare ribbon wire to build the connectors.

Each of the four groups had two connectors and which went to a separate MAX7219CNG soldered to a protoboard. Each board and headers where custom designed and hand soldered.  I could have ordered a custom PCBs, which would have shaved several days of work off, but that would have cost a lot more, so in an effort to keep the build costs down I did everything by hand.  There is a lot in information on using the 7219 chips with arduinos and the Led Matrix library does most of the hard work for you.  On the hardware end, basically they are chained together and require a resistor and two capacitors, beyond that it is just a matter of connecting the right pins to the right led row.  Once that was finished, I connected everything tested out a few patters and attached the array to the inside of the helmet.  Using some night shade car tint spray and another bent piece of plexiglass, I had the helmet all covered and almost finished.

The final parts where the ear and side lights.  Using a separate fifth MAX7219CNG, I created 4 led  protoboards (two for each side/ear), the side lights where directly connected back to the 7219 board and the ear lights had separate headers as they needed to be threaded through a slit in the cardboard.  I mounted the side lights and build a little reflective holder that would defuse the bright leds of the colored rows.  Next, I had to cut out and round some plexiglass by hand to match the ear shapes.  The ends of soda cans covered the plexiglass and ear leds.  Then I masked off each exposed plexiglass piece on the helmet with masking tape and gave the entire thing a final coat of  rustoleum metallic spray paint.  Once again I could have worked out some form of chroming as others have done, but chroming along would add $100+ to the build price.  The metallic paint actually looks quite good despite laking the complete mirror reflection, the only issue is that it needs light spray passes, takes several days to dry, and can still be dulled by touching even after dry.  I just used the ears to put on the helmet, which kept the dulling in one place and avoided touching the main body as much as possible.  The lights tend to distract people anyway so it is not much of a problem unless you plan to wear this all the time. (Time two weeks of nights and weekends)

The final touches where the power supply and the programing.  I used a pololu power regulator as it covers the amperage requirements and could be reused as a breadboard power supply.  For the power supply, 8 AA batteries supplied 12v  to the regulator and where still ok power wise after all the Halloween festivities where over.  Then I wired up an arduino to all of the MAX7219CNGs and also to a separate row of three buttons that I could use to switch patterns. The arduino sketch can be found here.  It was interesting as I figured out a nifty way to use a array of vertical 8 bit char and then bit shift them into rows based on an offset, this let me create a quick java program to visually create the patterns and then enter the numbers into the array.  A few patterns needed special handling code but most where covered.  I have to give tekparasite extra credit, as while I had a few animations in mind I was looking for extra example from the actual Daft Punk helmets, he had actual videos of many very creative choices, some of which I included in my build.  (See video below!)

The end result was everything I expected.  The helmet had a few cosmetic inperfections here and there, but looked fine over all and the light effects made sure no one noticed right away as everyone was too busy watching in surprise.  I also believe I get some partial bragging rights as unless someone has not posted their project, this is the first DIY helmet to include all four working light sections (front, both side parts and ears) and be on youtube/blog for others to use as a reference.  Both Volpin and tekparasite who have have impressive helmets (with actual crome finish) where missing one of the four in the end result videos that where posted.  Hopefully this will inspire others to not give up due to cost and make budget restricted but still functional helmets in the future.

August 15, 2011

DIY ADC to DVI converter

 A while back I was able to grab a 17 inch LCD Cinema Display from electronic surplus for 5$, while this sounds like an amazing deal, there was one extra issue that made this more fun than just being able to use it without some effort on my part.  Older Apple Cinema Displays use an ADC connector which while similar to the popular DVI, is only supported on a few older G4 towers and video cards.  Luckily I already have a working G4 mirror door with a graphics card that has the connector.  My original mod to fix the broken power supply prevents me from using the ADC connector due to lack of the extra 24v line, so with the help of my trusty heat gun, off went the connector for external use in this project to build an ADC to DVI adaptor.

First off I started looking for other people that had done this before.  While there is not a lot of information beyond a few others that have succeeded, there is a retail converter from Apple, so it is possible.

 The pinouts are quite simple to folow as ADC shares a lot in common with DVI as they are both digital. ADC Pinout and DVI Pinout.  Basically you just need to strip the dvi cable to leave just enough wire to be usable and connect the data link 1 pins, plug and play pins and digital clock pins.  The for the most part com in pairs of three (+,-,gnd)  The link 2, analog and shielding is not needed.  I also found that grounding the hot plug was required for the display port to dvi adaptor I am using to detect the monitor.  Other video cards I tested with did not need this.  The DVI spec has more information on the correct use of the hot plug pin, however I just left it grounded as the ADC spec does not include this.

The final parts needed that are not included in the DVI spec are the power and usb connections.  The monitor itself has no power supply or plug, the ADC connector needs to supply this.  I had a spare dc plug connector, so I purchased a 24v power supply off of Amazon that could supply enough amps to meet the ADC spec.  Finally there is the USB connection.  The monitor has an internal usb hub built in, also it use the USB connection to pass information about the monitor.  Unless you have the power turned on, the monitor connected and it plugged into a usb port it will not display anything!  This freaked me out at first when I started testing my solder connections and though the monitor was dead when nothing appeared with just power and the DVI connecter plugged in.

If you see weird color pixels that get better by pinching the wires together than you will need shorter leads.  It took a few tries to get the wires short enough to prevent interference.  Eventually I got it right and low and behold after connecting everything I had a clear image on the monitor.

Oddly enough right after completing this project I received a tv that can function as an external monitor so this is not as needed anymore, but I always enjoy having a few classic apple products on display.

March 13, 2011

XBox 360 Dual Firmware Mod

After months of having a 360 that works except the Samsung dvd drive, I finally bought a spare dvd drive off of ebay and decided to try and transplant the firmware from my broken driver to the new one. While I am at it, I might as well make it dual boot between the good firmware and another hacked firmware for other obvious reasons.  Now you might be asking why go through all the trouble when you can just flash the new drive.  Well my old 360 dvd drive was quite dead, to the point that I literally ripped the plcc chip off of the board with full intention of doing a complete brain transplant!  Otherwise there was no easy or cheap way to get the drive firmware key.

The above picture was all the remained of the old board, the traces where ripped up by the epoxy that was placed quite evilly on, around and under the plcc chip.  I had removed this a few months ago and has it in a safe place, waiting to have the time to use it.  Now, if you are reading this planing to do the same, I give you a big warning, if you see blank epoxy on your board, give up now.  My replacement drive had clear epoxy that was nice and soft after heating with a heat run.  However the black on the original board only got brittle making it impossible to not break parts.

Next I went online looking up everything I could find on the firmware.  On the Samung drives, It is stored on a plcc chip next to the large hole in the board. Each chip has a unique key, so you need to have this before you can use any other drives. With my drive not talking to anything, transplanting the entire chip was my last resort.  Next I found it contained the steps to dual boot my old chip with the new drives one.  This way I did not need to try and remove the current plcc chip, which may destroy the board in the process.  However, it is quite a bit more work and on a whole different difficulty level.  Another warning, do not try to attempt a dual firmware setup unless you have a good soldering iron with temperature control and a very steady hand.  It is easy to get solder everywhere!

I started out with thin ethernet wire to connect the two chips. I connected all of the top lead first but quickly found it was too thick and needed to use the tiny individual strands from twisted christmas tree light wire.  Then it was easy to use long strands and connect the bottom lead first and then stretch and line it up with the top lead.  After each pair of pins where all attached correctly on a side I would trim the extra wire.

This was very delicate work, and preparing the leads was not easy, more then once I needed to carefully clean up a bridged solder connection between leads or wires.  Also it was important to completely tin each strand before trying to connect it, otherwise it would not stick.  The above picture shows how small each wire needed to be, with a penny for reference. These pictures where shown with a magnifying glass.

After that following the rest of the guide was easy, I found some spare 10K resistors and attached them to pin 4 and 15 as the guide shows.  This may differ from what others need to do, as I later needed to switch it to pin 5, as 4 caused the driver to make the 360 show a E65 error. Luckily I was persistent and kept poking otherwise I would have just assumed the drive was dead due to some error on my part.  So you may need to play with pins to get it to work on different drives.

After that I closed up the drive and connected it to the 360.  The drive boots up and reads disks, the old firmware reading games, and the new firmware without the correct key only shows everything as a dvd.  Next I need to get the drive key, but that is for another day.